TY - JOUR A1 - Morris, Mackenzie C. A1 - Kassam, Farzaan A1 - Bercz, Aron A1 - Beckmann, Nadine A1 - Schumacher, Fabian A1 - Gulbins, Erich A1 - Makley, Amy T. A1 - Goodman, Michael D. T1 - The Role of Chemoprophylactic Agents in Modulating Platelet Aggregability After Traumatic Brain Injury JF - Journal of surgical research N2 - Background: The pathophysiology behind the subacute but persistent hypercoagulable state after traumatic brain injury (TBI) is poorly understood but contributes to morbidity induced by venous thromboembolism. Because platelets and their microvesicles have been hypothesized to play a role in post-traumatic hypercoagulability, administration of commonly used agents may ameliorate this coagulability. We hypothesized that utilization of aspirin, ketorolac, amitriptyline, unfractionated heparin, or enoxaparin would modulate the platelet aggregation response after TBI. Methods: Concussive TBI was induced by weight drop. Mice were then randomized to receive aspirin, ketorolac, amitriptyline, heparin, enoxaparin, or saline control at 2 and 8 h after TBI. Mice were sacrificed at 6 or 24 h after injury to determine coagulability by rotational thromboelastometry (ROTEM), platelet function testing with impedance aggregometry, and microvesicle enumeration. Platelet sphingolipid metabolites were analyzed by mass spectrometry. Results: ROTEM demonstrated increased platelet contribution to maximum clot firmness at 6 h after TBI in mice that received aspirin or amitriptyline, but this did not persist at 24 h. By contrast, adenosine diphosphate- and arachidonic acid-induced platelet aggregation at 6 h was significantly lower in mice receiving ketorolac, aspirin, and amitriptyline compared with mice receiving saline at 6 h after injury and only arachidonic acid-initiated platelet aggregation was decreased by aspirin at 24 h. There were no differences in microvesicle production at either time point. Platelet sphingosine-1-phosphate levels were decreased at 6 h in the group receiving amitriptyline and increased at 24 h along with platelet ceramide levels at 24 h in the amitriptyline group. Conclusion: After TBI, amitriptyline decreased platelet aggregability and increased contribution to clot in a manner similar to aspirin. The amitriptyline effects on platelet function and sphingolipid metabolites may represent a possible role of the acid sphingomyelinase in the hypercoagulability observed after injury. In addition, inhibition of platelet reactivity may be an underappreciated benefit of low molecular weight heparins, such as enoxaparin. (C) 2019 Elsevier Inc. All rights reserved. KW - Trauma KW - Traumatic brain injury KW - Venous thromboembolism KW - Chemoprophylaxis KW - Sphingolipids Y1 - 2019 U6 - https://doi.org/10.1016/j.jss.2019.06.022 SN - 0022-4804 SN - 1095-8673 VL - 244 SP - 1 EP - 8 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Gulbins, Anne A1 - Schumacher, Fabian A1 - Becker, Katrin Anne A1 - Wilker, Barbara A1 - Soddemann, Matthias A1 - Boldrin, Francesco A1 - Müller, Christian P. A1 - Edwards, Michael J. A1 - Goodman, Michael A1 - Caldwell, Charles C. A1 - Kleuser, Burkhard A1 - Kornhuber, Johannes A1 - Szabo, Ildiko A1 - Gulbins, Erich T1 - Antidepressants act by inducing autophagy controlled by sphingomyelin-ceramide JF - Molecular psychiatry N2 - Major depressive disorder (MDD) is a common and severe disease characterized by mood changes, somatic alterations, and often suicide. MDD is treated with antidepressants, but the molecular mechanism of their action is unknown. We found that widely used antidepressants such as amitriptyline and fluoxetine induce autophagy in hippocampal neurons via the slow accumulation of sphingomyelin in lysosomes and Golgi membranes and of ceramide in the endoplasmic reticulum (ER). ER ceramide stimulates phosphatase 2A and thereby the autophagy proteins Ulk, Beclin, Vps34/Phosphatidylinositol 3-kinase, p62, and Lc3B. Although treatment with amitriptyline or fluoxetine requires at least 12 days to achieve sphingomyelin accumulation and the subsequent biochemical and cellular changes, direct inhibition of sphingomyelin synthases with tricyclodecan-9-yl-xanthogenate (D609) results in rapid (within 3 days) accumulation of ceramide in the ER, activation of autophagy, and reversal of biochemical and behavioral signs of stress-induced MDD. Inhibition of Beclin blocks the antidepressive effects of amitriptyline and D609 and induces cellular and behavioral changes typical of MDD. These findings identify sphingolipid-controlled autophagy as an important target for antidepressive treatment methods and provide a rationale for the development of novel antidepressants that act within a few days. Y1 - 2018 U6 - https://doi.org/10.1038/s41380-018-0090-9 SN - 1359-4184 SN - 1476-5578 VL - 23 IS - 12 SP - 2324 EP - 2346 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Gutbier, Birgitt A1 - Schönrock, Stefanie M. A1 - Ehrler, Carolin A1 - Haberberger, Rainer A1 - Dietert, Kristina A1 - Gruber, Achim D. A1 - Kummer, Wolfgang A1 - Michalick, Laura A1 - Kuebler, Wolfgang M. A1 - Hocke, Andreas C. A1 - Szymanski, Kolja A1 - Letsiou, Eleftheria A1 - Lüth, Anja A1 - Schumacher, Fabian A1 - Kleuser, Burkhard A1 - Mitchell, Timothy J. A1 - Bertrams, Wilhelm A1 - Schmeck, Bernd A1 - Treue, Denise A1 - Klauschen, Frederick A1 - Bauer, Torsten T. A1 - Tönnies, Mario A1 - Weissmann, Norbert A1 - Hippenstiel, Stefan A1 - Suttorp, Norbert A1 - Witzenrath, Martin T1 - Sphingosine Kinase 1 Regulates Inflammation and Contributes to Acute Lung Injury in Pneumococcal Pneumonia via the Sphingosine-1-Phosphate Receptor 2 JF - Critical care medicine N2 - Objectives: Severe pneumonia may evoke acute lung injury, and sphingosine-1-phosphate is involved in the regulation of vascular permeability and immune responses. However, the role of sphingosine-1-phosphate and the sphingosine-1-phosphate producing sphingosine kinase 1 in pneumonia remains elusive. We examined the role of the sphingosine-1-phosphate system in regulating pulmonary vascular barrier function in bacterial pneumonia. Design: Controlled, in vitro, ex vivo, and in vivo laboratory study. Subjects: Female wild-type and SphK1-deficient mice, 8-10 weeks old. Human postmortem lung tissue, human blood-derived macrophages, and pulmonary microvascular endothelial cells. Interventions: Wild-type and SphK1-deficient mice were infected with Streptococcus pneumoniae. Pulmonary sphingosine-1-phosphate levels, messenger RNA expression, and permeability as well as lung morphology were analyzed. Human blood-derived macrophages and human pulmonary microvascular endothelial cells were infected with S. pneumoniae. Transcellular electrical resistance of human pulmonary microvascular endothelial cell monolayers was examined. Further, permeability of murine isolated perfused lungs was determined following exposition to sphingosine-1-phosphate and pneumolysin. Measurements and Main Results: Following S. pneumoniae infection, murine pulmonary sphingosine-1-phosphate levels and sphingosine kinase 1 and sphingosine-1-phosphate receptor 2 expression were increased. Pneumonia-induced lung hyperpermeability was reduced in SphK1(-/-) mice compared with wild-type mice. Expression of sphingosine kinase 1 in macrophages recruited to inflamed lung areas in pneumonia was observed in murine and human lungs. S. pneumoniae induced the sphingosine kinase 1/sphingosine-1-phosphate system in blood-derived macrophages and enhanced sphingosine-1-phosphate receptor 2 expression in human pulmonary microvascular endothelial cell in vitro. In isolated mouse lungs, pneumolysin-induced hyperpermeability was dose dependently and synergistically increased by sphingosine-1-phosphate. This sphingosine-1-phosphate-induced increase was reduced by inhibition of sphingosine-1-phosphate receptor 2 or its downstream effector Rho-kinase. Conclusions: Our data suggest that targeting the sphingosine kinase 1-/sphingosine-1-phosphate-/sphingosine-1-phosphate receptor 2-signaling pathway in the lung may provide a novel therapeutic perspective in pneumococcal pneumonia for prevention of acute lung injury. KW - acute lung injury KW - pneumococcal pneumonia KW - sphingosine kinase 1 KW - sphingosine-1-phosphate KW - sphingosine-1-phosphate receptor 2 Y1 - 2018 U6 - https://doi.org/10.1097/CCM.0000000000002916 SN - 0090-3493 SN - 1530-0293 VL - 46 IS - 3 SP - e258 EP - e267 PB - Lippincott Williams & Wilkins CY - Philadelphia ER -